Method of and apparatus for pouring ingots



Jan. 26, 1965 R. E. DALEY METHOD OF AND APPARATUS FOR POURING INGOTS Filed March 20, 1962 INVENTOR.

BY my 3,166,806 METHGI) OF AND APPARATUS FUR POURING INGOTS Robert E. Daley, 8355 Remington Drive, Pittsburgh, Pa.

Filed Mar. 20, 1962, Ser. No. 181,015

3 Claims. (Cl. 22147) This invention relates to new and useful improvements in a method of pouring ingots and hot tops for use in connection therewith and it is among the objects thereof to provide a method of pouring metal into ingot molds which shall reduce to a minimum the croppage or excess metalresulting from hot topping, yet allow sufiicient sinkhead protrusion to withstand stripper crane bits for stripping the ingot from the molds.

It is still another object of this invention to provide a method of pouring ingots which shall cause gradual solidification of the ingot through the hot top and junction area, the metal initially solidifying at the top of the ingot mold thence through an intermediate cooling state above the mold at the junction of the hot top and finally through a very slow cooling stage at the upper portion of the hot top whereby the impurities are permitted to rise to the portion of the ingot that is sheared or cropped and also eliminates center segregation and porosity.

The invention will become more apparent from a consideration of the accompanying drawing constituting a part hereof in which like reference characters designate like parts and in which:

FIGURE 1 is a top plan view of an ingot and hot top for carrying out the method of the present invention;

FIGURE 2 is a vertical cross-sectional view of the upper portion of the ingot mold and hot top taken along the line 2-2, FIGURE 1;

FIGURE 3 is a side elevation viewed from the side through which the cross section of FIGURE 2 is taken;

FIGURE 4 is a vertical cross-sectional view of a modified form of hot top;

FIGURE 5 is a similar View of still another modified form of hot top and a portion of an ingot mold; and

FIGURE 6 a similar view showing a cavity in the cast ingot under certain operating conditions.

With reference to FIGURE 6 of the drawing, the numeral 1 designates an ingot mold, 2 a casting having centering flanges 3 and 4 for overlapping the upper edge of the ingot mold 1. The casting 2 is provided with an inner flange 5 that extends to the edge 6 of the ingot mold and the casting 2 is lined with a semi-permanent refractory insulating material 7 which seats on the flange 5 and extends to the top of the casting 2. The hot top casting 2 is also provided with trunnions 8 for engagement by crane hooks for stripping after the ingot has been poured and solidified. As shown in FIGURE 1, the ingot mold 1 also has trunnions 9 by which it may be engaged by crane hooks to lift the same.

The present invention is applicable to the pouring of metals using molds with the big end up in which case the ingot must be stripped from the mold by lifting it upward. The above-described structure is not new and permanent hot top castings with semi-permanent liners have been heretofore used. Such hot topping resulted in a formation of a carrot-shaped cavity, as shown at 10, FIGURE 6, which produced enough metal for the stripper crane bits without collapsing the sinkhead metal. This portion of the ingot was cut oil and amounted to about 15% of the total wei ht of the ingot.

In accordance with the present invention, the carrotshaped cavity 10 of FIGURE 6 is avoided by controlling the heat loss from the vsinkhead metal in the manner shown in FIGURE 4, for example, in which the lining material which is the semi-permanent lining designated by the numeral 11, extends only part way up on the United States Patent 0 Bdfihfidh Patented Jan. 26, 1965 ice inside of the hot top casting 2 and the upper portion of the liner designated by the numeral 12 consists of an exothermic material which generates heat, thus prolonging the fluidity of the sinkhead metal in the upper region of the hot top, with the result that when the metal has solidified, there will be a solid ingot a substantial distance above the junction 13 of the mold and hot top 1 and 2, respectively. When such an ingot is stripped by removing the hot top 2, there will be sufficient metal with the sinkhead walls sufficiently heavy to withstand the pressure of the stripper crane bit without collapsing and the loss of metal by cropping or shearing wlil be approximately '7 to 8% or one-half of that resulting from conventional hot topping.

In the structure shown in FIGURE 2, the semi-permanent lining designated by the numeral 14 extends the full length of the inside wall of the hot top casting 2 above the flange 5 to the top of the hot top. A partial inner lining 15 of exothermic material is provided to maintain fluidity of the poured metal at the top of the hot top for a 'suflicient length of time to allow feeding of the metal into the mold and lower portion of the hot top to form a solid ingot, as shown in cross section.

By utilizing the insert 15 in place of the half liner 12, FIGURE 4, both the height of the hot section and the degree of fluidity can be controlled.

In the modification shown in FIGURE 5, the liner '7 of semi-permanent refractory material such as that shown in FIGURE 6, is supplemented by an inner lining 16 which is of insulating material to reduce the heat loss of the molten metal in the upper region of the hot top without, however, supplementing the heat as when exothermic material isemployed, as shown in FIGURE 2.

By the use of the hot top castings, with semi-permanent liners of refractory material and the exothermic inserts, the metal when poured to fill the mold and to the top of the exothermic insert provides for a gradual solidification of the ingot through the hot top junction area going from a cold cast iron ingot mold 1 to an intermediate insulator of the semi-permanent refractory form to a very high insulated or exothermic section at the upper portion of the hot top.

Because of the sinkhead shape provided with this hot top and its extreme efficiency, it is possible to apply much of the ingot sinkhead material to the top bloom of an ingot cast with this hot topping process. The top crop that is sheared oil should consist mainly of the sinkhead shell, wnich is the tin wall section at the top of the cast metal in FIGURE 2, which remains after the ingot cavity has been filled, plus a nominal amount of solid metal which will include all of the non-metalics and contaminate metal of the ingot.

Although one embodiment of the invention has been herein illustrated and described, it will be evident to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

Iclaim:

1. The method of pouring ingots in cast iron molds having a hot top for receiving molten metal abovesaid mold which comprises:

(alpouring metal into the mold and hot top to a desired level of the molten metal above the mold,

(b) maintaining a high chill zone for the poured metal at substantially the junction of the mold and hot top,

(c) ,maintaining an intermediate temperature zone for the poured metal above the mold junction and" below the top zone of the hot top, and,

(d) maintaining a hot zone at the upper limit of the poured metalwithin the hot top to provide a controlled shape and minimum mass of metal for 'cropping.

2. A hot top for feeding molten metal to ingot molds and the like comprising a permanent casting having a bottom flange for seating on the top of the mold extending radially inward to the inner wall of the mold to constitute a shoulder for a renewable lining material, said ,flange being of substantial thickness to provide a high chill zone for the poured metal at the junction of the mold and hot top and a refractory liner supported on said flange shoulder extending the full length of said casting to constitute a heat insulating wall for the feed metal above the mold, the upper portion of said liner being exothermic to delay solidfication or the metal at the top.

3. A hot top for feeding molten metal to ingot molds and the-like comprising a permanent casting having a bottom flange for seating on the top of the mold extending radially inwardto the inner wall of the mold to constitute a shoulder for a renewable lining material, said flange being of substantial thickness to provide a high chill zone for the poured metal at the junction of the mold and hot References Qited by the Examiner UNITED STATES PATENTS 1,192,617 7/16 Gathniann 22-447 2,390,500 12/45 Charman et al 22-447 2,821,000 1/58 Nouveau 22-216.5

FOREIGN PATENTS 83 8,676 6/60 Great Britain.

Ml HAEL V. BRINDISI, Primary Examiner.

RAY K. WINDHAM, WILLIAM J. STEPHENSON, Examiners. 

3. A HOT TOP FOR FEEDING MOLTEN METAL TO INGOT MOLDS AND THE LIKE COMPRISING A PERMANENT CASING HAVING A BOTTOM FLANGE FOR SEATING ON THE TOP OF THE MOLD EXTENDING RADIALLY INWARD TO THE INNER WALL OF THE MOLD TO CONSTITUTE A SHOULDER FOR A RENEWABLE LINING MATERIAL, SAID FLANGE BEING OF SUBSTANTIAL THICKNESS TO PROVIDE A HIGH CHILL ZONE FOR THE POURED METAL AT THE JUNCTION OF THE MOLD AND HOT TOP, A REFRACTORY LINER SUPPORTED ON SAID FLANGE EXTENDING THE FULL LENGTH OF SAID CASTING TO CONSTITUTE A HEAT INSULATING WALL FOR THE FEED METAL ABOVE THE MOLD AND A SECOND LINER OF EXOTHERMIC METAL EXTENDING FROM SUBSTANTIALLY THE VERTICAL MID-SECTION OF SAID FIRST-NAMED LINER TO THE TOP THEREOF. 